The invention relates to a breaker panel and to a circuit breaker and to a seal for this circuit breaker.
Known breaker panels comprise:    a removable front cover comprising apertures; and            a plurality of circuit breakers, each circuit breaker comprising, at one end, a foot, and at the opposite end, a head received into the interior of a respective aperture of the front cover, this head comprising:                    a frustoconical portion that flares in the direction of the foot, from a top to its base; and            a shoulder, perpendicular to a plug-in direction, located level with the base of the frustoconical portion,                        the frustoconical portion comprising in immediate succession when traced from its base to its top:                    a frustroconical seal made of an elastomer, this frustroconical seal having a first frustroconical face exposed directly to the exterior and extending from a lower edge to an upper edge; and            a conic frustum made of a material that is harder than the material of the frustroconical seal, this conic frustum having a second frustroconical face directly exposed to the exterior and extending from a lower edge to an upper edge contained in the top of the frustroconical portion.                        
Such a breaker panel is disclosed in patent application EP 2 254 207 A1. In such a panel, the seal makes it possible to prevent repeated shocks between the head of the circuit breaker and the edge of the aperture ending in an untimely switching of the circuit breaker.
When a defective circuit breaker is replaced, it is generally not only necessary to replace the circuit breaker but also its seal. However, if the seal is fastened to the aperture and not to the circuit breaker, as described in the embodiment in FIG. 4 of patent application EP 2 254 207 A1, then frequently either it is forgotten to change the seal or the seal is lost.
The embodiment in FIG. 6 of patent application EP 2 254 207 A1 avoids this drawback since the seal is fastened to the head of the circuit breaker. This makes it possible to replace in a single operation both the circuit breaker and the seal. In contrast, with the embodiment in FIG. 6 of patent application EP 2 254 207 A1, it is difficult to mount the front cover on the heads of the circuit breakers. Specifically, the rims of the apertures of the front cover are generally made of metal. During mounting, these rims rub directly against the frustroconical seal, which is made of an elastomer. Given the difference in hardness between the metal edge and the seal, the front cover does not slide easily over the frustroconical portion of the circuit breakers. This makes it very difficult to centre the heads of the circuit breakers in the middle of the apertures especially when the number of circuit breakers is high. Here, the number of circuit breakers is considered to be high when it exceeds ten or fifty circuit breakers. In addition, the rubbing of the metal on the elastomer rapidly wears the frustroconical seals.